Four-way expansion earth anchor



April 357 J. A. TOEDTMAN 3,31

FOUR-WAY EXPANSION EARTH ANCHOR Filed July 2, 1964 F/G. 3. j

47 INVENTOR.

N 2 JOHN A TOEDTMA ATTORNEY.

United States Patent poration of Missouri Filed July 2, 1964, Ser. No. 379,879 4 Claims. (Cl. 52-160) This invention relates generally to improvements in an earth anchor, and more particularly to an improved twopiece, four-way expansion type anchor.

The present invention constitutes an improvement over the earth anchor disclosed in U.S. Patent No. 2,678,706 in which upstruck tabs on the side margins of the underlying plate interfit slots formed in the bending zones of the overlying plate and are bent over the overlying plate in order to hold the blade members in assembly.

In such heretofore conventional anchor, the impact surface was not fiat because of the overlapping engagement of the tabs. Moreover, the pounding on the impact surface including the tabs incident to expansion of the blades tended to drive the tabs out of retention with the overlying plate and thereby adversely affected the connection of the blade members. In addition, the opening of the blades tended to reduce the grip of the tabs on the overlying plate.

It is an important object of the persent invention to overcome the above stated disadvantages by providing an interconnection between the superimposed plates of the blade members which achieves a relatively flat impact or overlying plate surface to receive the hammer blows used to expand the anchor, and which tends to increase interlocking engagement upon such expansion.

An important object is realized by providing a novel interconnection of a pair of double-lobed blade members. Each blade member includes a pair of earth-gripping blade lobes interconnected by an integral intervening plate, the blade members being disposed in substantially right angular relation with the plate of one superimposed upon the plate of the other. The overlying plate includes integral tabs struck downwardly and extending through slots formed in the underlying plate to provide a connection that holds the plates together.

The functional advantages are attained by the structural arrangement in which the tabs have their free ends spaced inwardly of the region of integral connection with the plate, and in which the tabs are inclined downwardly and inwardly toward each other in opposed relation, the tabs being spaced inwardly from the side edges of the overlying plate.

The functional advantages are achieved by the provision of aligned central openings in the superimposed plates through which the anchor rod extends, and by the disposition of the integral tabs in being struck downwardly from opposite sides of the central opening of the overlying plate and so that their free ends extend toward each other in downwardly inclined, inwardly opposed relation.

Another important object is afforded by making the Width of the overlying plate greater than the distance between the bending zones of the underlying plate, and by arranging the inwardly and downwardly opposed tabs on the overlying plate so that they extend through slots provided in the bending zones of the underlying plate, and hence effectively interconnect the superimposed plates.

Still another important object is realized by providing the intervening overlying plate with a pair of substantially 3,315,423 Patented Apr. 25, 1967 U-shaped cuts, one on each side of the central opening of such plate, the substantially U-shaped cuts being arranged in opposed relation so that their bottom portions extend toward each other to present a pair of tabs with three ends extending toward each other adjacent the central opening and having integral connections at the outer sides of such plate yet spaced inwardly from the side edges.

Yet another important object is to provide an expansion type earth anchor that is simple and durable in construction, economical to manufacture and assemble, highly efficient in operation, and which can be utilized by anyone with little or no instruction.

The foregoing and numerous other objects and advantages of the invention will more clearly appear from the following detailed description of a preferred embodiment, particularly when considered in connection with the accompanying drawing, in which:

FIG. 1 is a top plan view of the earth anchor;

FIG. 2 is a cross sectional view as seen along line 22 of FIG. 1, the expanded position of the blade members being illustrated in broken lines, and

FIG. 3 is a fragmentary perspective view showing the structure and interconnection between the intervening plates of the blade members.

Referring now by characters of reference to the drawing, and first to FIG. 1, it will immediately be apparent that the earth anchor is of the two-piece, four-way expansion type. The anchor assembly includes a pair of blade members generally referred to as 10 and 11, each of which is preferably stamped from a single blank of relatively heavy gauge sheet metal.

The blade member 10 consists of a pair of earth-gripping blade lobes 12 integrally interconnected by an intervening plate 13. The intervening plate 13 is defined between spaced transverse bending zones 14. Similarly, the other blade member 11 consists of a pair of earth-gripping blade lobes 15 integrally interconnected by an intervening plate 16. The intervening plate 16 is defined by spaced transverse bending zones 17.

These blade members 10 and 11 are each folded to a substantially inverted U-shaped structure, and are so designed and arranged that in folded assembly, as shown in FIGS. 1 and 2, the blade members 10 and 11 are nested, the one blade member 10 overlying the other blade member 11. The blade members 10 and 11 are disposed in a position. with their respective longitudinal axes in a substantially right angular relation. The plate 13 of blade member 10 is superimposed upon the plate 16 of the other blade member 11.

When the blade members 10 and 11 are disposed in the folded, non-gripping or initial assembly, the depending blade lobes 12 and 15 respectively extend downwardly so that their pointed blade edges 20 seat upon the rounded peripheral edge 21 of the strain plate 22 constituting a blade-expanding member which will be described later in more detail.

The overlying plate 13 seating on and connected to the underlying plate 16 presents a substantially fiat horizontal surface adapted to receive the impact blows of a hammer.

The width of the underlying plate 16 is appreciably less than the width of the overlying plate 13, and is substantially equal to the distance between the bending zones 14 of the overlying plate 13. Moreover, the width of the overlying plate 13 is appreciably greater than the distance between the bending zones 17 of the underlying plate 16 so that the side edges 23 extend beyond the 3 bending zones 17 of the'underlying plate 16 in overhanging relation.

The overlying plate 13 includes a central circular opening 24 through which an anchor rod 25 extends. Two rectangular openings 26 are stamped in the overlying plate 13, one on each side of the anchor rod opening 24 through and symmetrical with the longitudinal axis of the blade member and in the bending zones 14. These rectangular openings 26 effectively reduce the cross sectional area of the blade member 10 in the bending zones 14 in order to provide for -a more ready and effective bending in the zones 14 upon expansion of the anchor.

Formed in the overlying plate 13 are a pair of substantially U-shaped cuts generally indicated as 27, one cut 27 being located on each side of the circular rod opening 24. The substantially U-shaped cuts 27 are arranged so that their bottom portions 30 face inwardly toward each other and toward the center opening 24 and so that their spaced side portions 29 extend laterally outward toward the side edges 23. Each of these substantially U-shaped cuts 27 forms a tab 31 having an integral connection with the intervening plate 13. The free ends of the tabs 31 are struck downwardly and are inclined at an angle inwardly toward each other. It will be noted that the tabs 31 are located inwardly of the side edges 23.

The underlying plate 16 is provided with a central opening 32 aligned with and in register below the co operating central opening 24 formed in the overlying plate 13. The anchor rod 25 extends freely through these aligned central openings 24 and 32.

A pair of slots 33 are provided in the underlying plate 16, and specifically, one of the slots 33 is located in each of the bending zones 17 symmetrical with the longitudinal axis of the blade member 11. These slots 33 are situated immediately below the coacting tabs 31. The length of each slot 33 is slightly greater than, yet closely approximates, the width of the associated tab 31.

When the blade members 10 and 11 are disposed in nested relation with the intervening plate 13 superimposed on the intervening plate 16, all as described previously, the tabs 31 extend through the slots 33. Because of the inclination of the tabs 31, the tabs 31'will extend inwardly below the underlying plate 16. In order to provide an even more effective connection, the free ends of the tabs 31 are struck a sharp blow to clinch the tabs 31 in place. This structure is suggested by the slightly curved configuration of the tab ends as shown in cross section in FIG. 2.

It will be importantly noted that because of this particular interconnection between the plates 13 and 16 as provided by the interfitting relationship of tabs 31 in slots 33, the overlying plate 13 is substantially flat, and therefore affords an impact surface that is flat to receive the blows of the expanding hammer. These hammer blows do not engage the tabs 31 directly. Because of the structural arrangement of such tabs 31 relative to each other and their interconnection in the slots 33, the impact blows of the hammer tend to increase the lock- 11n6g engagement of the tabs 31 with the underlying plate Each blade lobe 12 and is curved such that its outer pointed edge is directed outwardly relative to the center zone thereof, and each blade lobe contains a relatively deep-pressed rib 34 extending along the longitudinal axis, the rib 34 strengthening the blade lobes 12 and 15 against transverse bending stresses.

The margins of the overlying blade member 10, connecting the outer tapered edges 20, have a slight inward curve leading from the tip and merging with an outwardly turned side flange 35 formed along each side of approximately the upper one-half portion of the blade lobes 12. The margins, connecting the tapered edges 20 of the underlying blade member 11, converge slightly upwardly to the integral intervening plate 16. The blade lobes 15 of the blade member 11 also contain outwardly turned side flanges '36 in the same region as do the blade lobes 12 of the overlying blade member 10. The existence of these side flanges 35 and 36 in the respective blade members 10 and 11, permits the shown and described interfitting nesting relation of the blade members both during the folded initial position shown in full lines in FIG. 2 and in the expanded position shown in broken lines in FIG. 2. Yet these side flanges 35 and 36 provide the maximum amount of earth-gripping blade area.

The strain plate 22 is stamped from a blank of heavy gauge metal, and is provided with a circular aperture 37 in the center that is aligned directly below the cooperating circular openings '24 and 32 formed in the superimposed plates 13 and 16, the anchor rod 25 extending through the circular aperture 37 and below the strain plate 22. The upper surface 40 of the strain plate 22 slopes downwardly from the central area around the circular opening 37 to the rounded peripheral margin 21 that is adapted to guide and direct the blade lobes 12 and 15 into distended earth-engaging positions upon tamping of the anchor. A downturned peripheral flange 41 extends from the rounded peripheral margin 21.

A wire 42 is inserted through a pair of openings 43 formed in the tapered edge 20 of each blade lobe 12 and 15, the wire 42 extending through corresponding openings 44 formed in and near the periphery of the strain plate 22. The wire 42 is twisted to lock the blade members 10 and 11 in folded assembly as illustrated in FIGS. 1 and 2, until the blade lobes 12 and 15 are sheared free of the wires by the initial blows of the percussion tool.

A nut-retaining element 45 is located around the anchor rod aperture 37 and is secured as by welding to the underneath surface of the strain plate 22. The lower surface of the nut-retaining element 45 is provided with a circular opening 46, the margins defining such circular opening 46 providing a bearing surface for the threaded lower end 47 of anchor rod 25 so as to preclude excessive iwobbling. The nut-retaining element 45 receives and closely fits a nut 50 that is threadedly attached to the threaded rod end 47 Rotation of nut 50 is prevented by the nut-retaining element 45, thereby enabling the removal of the anchor rod 25 while the anchor is in its spread operative position under ground.

It is thought that the usage and functional advantages of the expansion earth anchor have become fully apparent from the foregoing detailed description of parts, but for completeness of disclosure, the assembly and installation will be briefly described.

The initial assembly of the anchor is shown by the drawing. The blade members 10 and 1 1 are folded along the bending zones 14 and 17 respectively to the inverted substantially U-shaped illustrated, and the blade member :10 is placed over the cooperating blade member 11 so that the intervening plate 13 is superimposed upon the intervening plate 16, and so that the respective longitudinal axes of the blade members 10 and 11 are in substantially right angular relation. The lower tapered edges 20 of the blade lobes 12 and 15 are seated upon the peripheral rounded margin 21 of the strain plate 22, and are locked in position by the insertion of lock wires 42 in and through the compatible blade holes 43 and strain plate holes 44, the wires 42 being twisted securely. The anchor rod 25 is inserted through the uppermost circular openings 24 and 32 formed in the superimposed plates 13 and 16, and is inserted through the strain plate circular opening 37 for threaded engagement of the threaded rod end 47 with the nut 50 contained in the nut-retaining element 45.

In assembling the blade members 10 and 1 1, the downwardly inclined tabs 31 are inserted through the coacting slots 33 in order to connect the superimposed plates 13 and 16 together. The outermost ends of the tabs 31 are struck to clinch the tabs 31 more effectively against the under side of the underlying plate 16. It will be noted that with this connection the overlying plate 13 seats flat on the underlying plate 16, and that the overlying plate 13 provides a substantially flat impact surface for the tamping tool.

On the job site, a hole of desired depth is formed in the ground, and the anchor is inserted. A suitable tamping tool (not shown) is employed to strike the flat impact surface provided by the overlying plate 13 of the blade member :10. The initial tamping blows shear the wires 42 and commence the penetration of the blade lobes 12 and 15 into the surrounding earth. During the expansion of the blade lobes 12 and 15, the blade members and 11 bend in the bending zones 14 and 17 respectively. The blade members are deformed from the folded position illustrated in full lines in FIG. 2 to the completely expanded position illustrated in broken lines. In the fully expanded position, the intervening, superimposed plates 13 and 16 are brought down upon and close to the upper surface 40' of the strain plate 2 2.

Of course, during the entire tamping operation the superimposed plates 13 and 16 are maintained in operative connection by the insertion of the downwardly inclined tabs 31 in the compatible slots 33. In fact, the tamping action tends to increase the effective locking engagement of the tabs 31 with the underlying plate 16.

Although the invention has been described by making detailed reference to a single preferred embodiment, such detail is to be understood in an instructive, rather than in any restirictive sense, many variants being possible within the scope of the claims hereunto appended.

I claim as my invention:

1. An expansion earth anchor comprising:

(a) a pair of blade members, each blade member including a pair of blade lobes integrally interconnected by an intervening plate defined between spaced transverse bending zones, the blade members being disposed in substantially right angular relation with the plate of one superimposed upon the plate of the other,

(b) the width of the overlying plate being greater than the distance between the bending zones of the underlying plate to provide an overhang beyond the bending zones,

(c) the underlying plate having slots substantially in the bending zones,

(d) the overlying plate having integral tabs spaced inwardly from the side edges of said plate and struck downwardly to extend through the slots in the bending zones of the underlying plate to secure the plates together, the tabs being spaced inwardly to allow the overhang to increase the impact plate surface of the overlying plate,

(e) a strain plate engaging the blade lobes, and

(f) an anchor rod extending through the superimposed plates and attached to the strain plate.

2. An expansion earth anchor comprising:

(a) a pair of blade members, each blade member including a pair of blade lobes integrally interconnected by an intervening plate defined between spaced transverse bending zones, the blade members being disposed in substantially right angular relation with the plate of one superimposed upon the plate of the other,

(b) the width of the overlying plate being appreciably greater than the distance between the bending zones of the underlying plate so as to provide an overhang beyond the bending zones,

(c) the underlying plate being provided with slots substantially in its bending zones,

(d) the overlying plate having integral tabs struck downwardly,

(e) the tabs having free ends spaced inwardly of the region of integral connection of the tabs with the said plate so as to enable insertion of the tabs through the slots in the bending zones and yet provide the overhang that increases the impact plate surface of the overlying plate, the tabs being disposed in inwardly facing opposed relation,

(f) the tabs extending through the slots and under the underlying plate to secure the plates together,

(g) a strain plate engaging the blade lobes, and

(h) an anchor rod extending through the superimposed plates and attached to the strain plate.

3. An expansion earth anchor comprising:

(a) pair of blade members, each blade member including a pair of blade lobes integrally interconnected by an intervening plate defined between spaced transverse bending zones, the blade members being disposed in substantially right angular relation with the plate of one superimposed upon the plate of the other, the superimposed plates having aligned central openings therein,

(b) the underlying plate being provided with slots substantially in the bending zones,

(c) the overlying plate having integral tabs struck downwardly from opposite sides of the central opening of said plate,

(d) the tabs having their free ends disposed adjacent the central opening of the overlying plate and inclined toward each other in inwardly facing opposed relation,

(e) the tabs bing spaced inwardly from the side edges of the overlying plate so as to enable insertion of the tabs through the slots in the bending zones and to provide an overhang beyond the bending zones which increases the impact plate surface of the overlying plate,

(f) the downwardly inclined tabs extending through the slots and under the underlying plate to secure the plates together,

(g) a strain plate engaging the blade lobes, and

(h) an anchor rod extending through the central openings and attached to the strain plate.

4. An expansion earth anchorcomprising:

(a) a pair of blade members, each blade member including a pair of blade lobes integrally intercomnected by an intervening plate defined between spaced transverse bending zones, the blade members being disposed in substantially right angular relation with the plate of one superimposed upon the plate of the other,

(b) the plates being provided with aligned central openings,

(c) the width of the overlying plate being appreciably greater than the distance between the bending zones of the underlying plate so as to provide an overhang beyond the bending zones,

(d) the underlying plate being provided with slots in the bending zones,

(e) the overlying plate being provided with a pair of substantially U-shaped cuts, one on each side of the central opening of said plate, the substantially U- shaped cuts being arranged in opposed relation with the bottom portions of such cuts arranged toward each other and the side portions extending laterally outward toward the overhang at the sides of the plate, the U-shaped cuts being arranged to provide a pair of tabs extending toward each other and having an integral connection at the outer sides yet spaced inwardly from the side edges of the overhang to enable the overhang to increase the impact plate surface,

(f) the tabs being struck downwardly and inclined toward each other in inwardly facing opposed relation,

(g) the tabs extending through the slots and clinched under the underlying plate to secure the plates together, the tab connection providing a flat impact plate surface on the overlying plate and tending to increase interlocking engagement upon expansion,

(h) a strain plate engaging the blade lobes, and

8 (i) an anchor rod extending through the central open- 2,678,706 5/ 1954 Pieper 52-160 ings and attached to the strain plate. 3,239,974 3/ 1966- Pieper 52-160 References Cited by the Examiner FRANK L. ABBOTT, Primary Examiner.

UNITED STATES PATENTS 5 RICHARD W. COOKE, JR., Examiner. 2,633,212 1953 Steinmayer R. s. VERMUT, Assistant Examiner.

2,658,590 11/1953 Hollander 52-160 

1. AN EXPANSION EARTH ANCHOR COMPRISING: (A) A PAIR OF BLADE MEMBERS, EACH BLADE MEMBER INCLUDING A PAIR OF BLADE LOBES INTEGRALLY INTERCONNECTED BY AN INTERVENTING PLATE DEFINED BETWEEN SPACED TRANSVERSE BENDING ZONES, THE BLADE MEMBERS BEING DISPOSED IN SUBSTANTIALLY RIGHT ANGULAR RELATION WITH THE PLATE OF ONE SUPERIMPOSED UPON THE PLATE OF THE OTHER, (B) THE WIDTH OF THE OVERLYING PLATE BEING GREATER THAN THE DISTANCE BETWEEN THE BENDING ZONES OF THE UNDERLYING PLATE TO PROVIDE AN OVERHANG BEYOND THE BENDING ZONES, (C) THE UNDERLYING PLATE HAVING SLOTS SUBSTANTIALLY IN THE BENDING ZONES, (D) THE OVERLYING PLATE HAVING INTEGRAL TABS SPACED INWARDLY FROM THE SIDE EDGES OF SAID PLATE AND STRUCK DOWNWARDLY TO EXTEND THROUGH THE SLOTS IN THE BENDING ZONES OF THE UNDERLYING PLATE TO SECURE THE PLATES TOGETHER, THE TABS BEING SPACED INWARDLY TO ALLOW THE OVERHANG TO INCREASE THE IMPACT PLATE SURFACE OF THE OVERLYING PLATE, (E) A STRAIN PLATE ENGAGING THE BLADES LOBES, AND (F) AN ANCHOR ROD EXTENDING THROUGH THE SUPERIMPOSED PLATES AND ATTACHED TO THE STRAIN PLATE. 